The present invention relates to a braking device for the rotor shaft of an open end rotor spinning machine, and more particularly to such a braking device used in the spin box of a rotor spinning machine in which the rotor shaft is supported in a pair of spaced bearing discs.
In the operation of open end rotor spinning machines, the rotor is occasionally stopped when a yarn break occurs or when a bobbin change is necessary, or at other occurrences. When this happens, a braking device is used to stop rotation of the shaft.
It has been observed that when the rotor shaft is out of operation that trash in the form of yarn softeners, yarn fragments and dust have accumulated between the contact surfaces of the bearing support discs and the rotor shaft, with the result that the rotor is no longer capable of running smoothly and evenly upon resumption of operation.
With prior art braking devices, a rotor brake acts through a brake shoe that either presses down against the rotor shaft between and at a spacing from the bearing support discs or acts upwardly against the rotor shaft between the bearing support discs to press the shaft against an auxiliary bearing member. With these braking devices the rotor shaft is engaged between the rotor discs and not within the rotor shaft support areas of the bearing support discs. Thus, the prior art braking devices can serve no purpose in eliminating or reducing contamination from trash and consequential uneven rotation of the rotor shaft on the bearing support discs.
The present invention is directed to eliminating or minimizing trash that accumulates on the bearing support discs and supported rotor shaft, by utilizing a new and improved braking device.